Reciprocating mechanism



Junel?, 1930. D RGRAHAME h 1,764,560

RECIPROCATING MECHANISM INVENTOR 4 DALL/l/-TGRHHAME June 17, 1930. I D. F. GRAHAME REGIPROCATING MECHANISM Filed Sept. 24, 1924 3 Sheets-Sheet 2 INVENTOR DHLLS EGFMHHME BY im QQQ ATT NEY June 17, 1930 D. F. GRAHAME l#764,560

n RECIIROGATING' MECHANISM Filed sept. 24, 1924 3 sheets-sheet s Patented' June 17, 1930 L-UNlrao srar :Pdlmf@NICE l` DALLAS r. eitAnAiaE, or Wns'riviocnrr, eUnBnd'cANAnA, Assieme To iaiLEYs'ioxEn 'COBPQRATIOM or WoRcns'rER, MASSACHUSETTS, A conroaAfrioN or,"iviAssAoHUr-` A SETTS niicirnocAiiNe ivir.eiiAnisM Application filed September 24, 1924.- Serial No. 739,701.2-

' My invention relates to reciprocating mechanisms-,and more particularly to a mechani-V cally operated mechanism for reciprocating the ram of a stoker orany otherelement which A `is to be moved in alternate directions at a uniormrate. v i y V v l Y Coalis ordinarily ed into the combustion chamber ota stoker by-means of a ram which is reciprocated past the opening otk a` coal hopper in such a manner as to 'force the coal intermittently into the furnace. This ram is ordinarily operated by means of a crank driven by a vvorm` gear mechanism. This type of drive, as heretofore constructed, has resulted in a large loss of power due not/only to the low efficiency of. thedriving mechanism but particularly to the fact that considerable 'rieo tion Agenerated by the lateral pressure -oi thecrank arm on the ram. It is notpossible to lubricatethe ram .owing to the presence of coal dust, hence anyllateral pressure is highly l' objectionable because of the friction losses as veil asthe Wear on the ram and its casing.

Itis themaiii object of my invention to n overcome these difiiculties and to providera simpliiied v`construction rfor a reciprocating mechanismvvhich `may be easily built and quickly assembledandwhich will have a relatively'high efficiency l l f It isa further objectoi1 my invention to provide a mechanical movement for'reciproeating bodies oit-various typeswhich is so constructed that a rotary unidirectional mo tionfm'ay be eiiiciently converted into a linear ,i'eciprocatorymotion. i n .Y It is a "furtherobject' of myvinvention to :provide ya stoker `4ram o driving mechanism which Will give adongitudinal straight thrust upon theramand sure andhigh `iictional losses andpyvhichis so constructedthatk if.k A.a battery `is employed any individual ram may be ,sepa-V rately cmitrollecl irrespective of the operation ofthe otherrams. y' y' With these' and otherobjects-iiivievvas VWill kbe Vapparent in the i"olloivingvl disclosure,v my invention resides in' i yset/forth in the specicationand covered by the'claims appended hereto.

Referring to the" djraivings,`

"tory linear Y anut which are soconstructed and arranged f ",by rotating the screw relative l This reverse movement of the screw lmay be Y caused by rotatingtle'screw in the same dithus eliminate lateralfpres-y oit jstoker. rams ingsL comprisesa hollow Worm one endareduced portion2l` carrying flanges the combination lof 'parts 22 arranged 'tov formlwith thrustbearing which permits rotation of` the iii 1 which 'like reference numerals indicate like parts, I have there illustrated vention as applied to a stoker in Which Fig lisa' vertical section through the center of the reciprocating mechanism Fig. 2 isan tion to` show ydetails ci the construction;

y g. Sis an enlarged sectional detailshowy ing the manner .of connecting the Worm to its supporting key shaft; K

Fig.l 4 is an end elevation showing a plurality of stoker Arams drivenfrom a common Adriving shaft;.and f f Fig. 5 is an enlarge showing the arrangement of the ram, itsdriving mechanism and the Stoker. A

'The application of a ,mechanically operated reciprocating mechanism embodying my ine,v vention to one type oi stokeri's illustratedin the drawings, inv which Vthe yreciprocating mechanism l() is direct-ly connected to the stoker ram 11 which is rec-iproc'able in the casing l2 beneath and past the throat of the hop per i3 through which coal'is ediiito thefurnace;V This coal-is passed through" an opening Vin ythefrontwall 14; of; the `furnace intothe retort 15 of thestoker. l

` In accordance vWith my' invention, I propose to convert afrotarymotion into a reciprocaone by employing a screw and that the screw An'iaybeheld romrotation and Amoved longitudinallyy byrotaton of the nut, y or it maybe movedlinf the i to` the nut.

rection as thenutfbut ata higher rate An automatically :operated clutch vmechanism may be'employed tohold the screwfy stationaryk at onetimeandto cause-its rotationat another Y time,` whereby the reciprocatofrymotion of thesc'rew is insured:-V f

. The enibodiment illustrated theirdravvdwhich 4has" at the;` member 23 a Worm." The'bearing" member 23 is connected to the rainllby means ofthe pin 24. The

oneV embodiment of my ind `viewr partly in section f .55 Aend elevationwith parts in sec-y n opposite direction i nut 30 which may Q50 vwill rotate faster 'than the i from an inner Vdriven from a chain Vlustrated in Figs. 2 v41 may be suitably ltionary meml arranged to be brought into mesh. posite side of the worm is slidably keyed to the key kshaft 25 mounted within the worm by means of a set of keys 26 which are slidable in their key ways on the shaft as longitudinal movement but are permitted to rotate by providing them with upturned lugs 27 rotatably mounted in an internal annular groove of the collar 28 Ywhich is fixed to the end of the casing 29. This construction perf mits the'worm and the key shaft to rotate as well as to move longitudinally. y t 1 y Threaded onto the worm is an elongated but is shown as anintegral member for the sake of clearness ofv illustration. This nut 30 has a reduced end portion 31 rotatably mounted inthe hub 32 which `is supported Wall ofthe casingV 29. lThe other-.end of the nut has a reduced portion 34 which islikewise mountedwithin Va radial bearing 35 fixed Vto thepcasing wall. Ball bearings 36 may be employed to take up the end thrust on thenut.VV

The nut is adapted to be rotated in one direction by means ofa gear 40 which is fixed to the nut an-dhere shown as integral therewith. This gear 40 is driven by a Worm 4l which in turn is rotated by a sprocket 42 43 connected to a motor or other suitable driving mechanism. As iland 4, this driving worm mounted in radial and thrust bearings and connected to the worms f.' of' other driving mechanism in alignment therewith bv a flexible coupling 44 of suitable construction.

' A further gear 46 `(Fig. l) formed onV the outside of the nut 30 meshes. with a gear47 keyed'to thev short shaft 48 which is suitably mounted on Vthe casing. A further gear 49 connected to the gear 47 in turn meshes with a gear 50 whichis mounted on the nut 36 to rotate relative thereto.

arranged as to prevent thegear 50 from -moving laterally inl its bearing. These'variou's gears are of such'shape and size that the gear gear 40'and in the present embodiment at twice the speed,

"so that the forward and reverse motions of the worm may be at the same speed. Y

In order to hold the worm from rotation p p 'at one time and permit it to rotate at another, "tti I Y provide a clutch mechanism which comprises `aistationary member54 mounted con- 'centric with" tue key shaft 25.- Y A movable.V

56 is keyed to the shaft 25and;

.clutch member mounted within the member 54. v*The vstacr54 and the movable clutch member 56 are provided with clutch' teeth 57 `The op-vv movable clutch member 56 is provided with teeth 58 which are arranged to mesh with teeth 59 projecting from the well asthe inner wall ofA the worm. These keys are prevented fromY Y tion, and

be made in several parts` inwardly the collar 67 which is i A thrust member 5lY 4is integrally fixed to the casing wall and so side of the gear 50. Springs 60 and 6l are provided on opposite sides of the shiftable clutch member to aid in shifting the same. A It will now be seen that when the clutch member 56 is in the position illustrated in F ig. l, the key shaft 25, which is slidably keyed to the clutch member 56, is prevented from rotating. The worm 2O slidably keyed toshaft 25 is likewise prevented from rotaas the nut 30 is ydriven bythe sprocket 42 rotating in the direction illustrated by the arrow a in Fig. l, the worm 20 and therefore the ram l1 are caused to move laterally in the direct-ion of the arrow Z). Alf now the clutch is thrown to connect the teeth 58V and 59, the key shaft and therefore the worm will be connected to the gear 50 which rotates at twi'cevthe speed of nut 30. The worm will then be caused to vrotate in the same direction as the nut but at a much faster speed, and it will accordingly be drawn back ward through thenut so as to reverse the direction of the ram and return it to its oriffinal position.

VInorder that thisfreversal of motion may be caused automatically, I provide the inner portion of the worm 20 with a shoulder 65 (Fig 3) which is arrangedto contact vwith an enlargement 66 on the end of the key shaft 25` when the worm has reached the desired outward limit of motion. This serves to move pinned to the key shaft and thereby compress the spring A6l which in turn pushes against the clutcli disconnects the clutch teeth '57, therebyy throwing the clutch member to member 56 and reverse the movement of the worm. At this time the worin 20 is at its outward limit of Vwithin the stoker may endanger the mechanism, hence I provide a safety feature which permits the worm to stand still if .an obstruc tion is met when the worm. is travelling outwardly andthe stoker ram isV pushing vfuel into the furnace. To this end, I so construct ftheparts that the stationary clutch member 54 mayV rotate if the pressure thereagainst is above'a certainv maximum, kand thusV permit the worm to rotate fre-ely lwith the nut.V This may be accomplished as illustrated by mounting the Y member 54 rotatably Von the collar 67 and clutch `member with thekey mentor" the member 54 by means of a yoke onthe clutch 'member which isheld by an adjustable pin 76 mounted on a lug on the end of the 'casing `29.

i 56 'which are concentric shaft, and 'prevent end mover YrIhe member 54 is also provided with a single tooth7 8 (Figs. 1 and 2) which is normally held by a tooth 79 on a sleeve 80. This sleeve is pinned to tliebar 8l which is in turn -rotatably mounted in suitable bearings in theftop of the casing. yA collar 84 fastened on the rod Sloutside of the casing is normallyk pinned in place by av shearing pin 85 which is made of such sizeand material that if too great a pressure is placedy on it it will shear oil. When the pressure ofr tooth 78v on the tooth 79 is excessive, the pin 85 shears and the rod 8l and the member 80 slide longitudinally until the tooth 78 loses Contact with tooth 7 9 and permits rotation'of the normally Vstan tionary clutch member 54.

If it isidesired to stop the operation of the reciprocating mechanism, as for instance when any particular retort has acquired more coalk than thel neighboring retort,.then by turning the handle 87 on rod 8l through Va suiiicient arc, the clutch tooth 79 is released sideways from engagement with the tooth 7.8 and the clutch member' 54 is permitted to revolve. In order to start the ram mecha nism into operation it is merely necessary` to push down on the handle 87 and bring the tooth 79 into the path of the tooth 78 and if the pin is in place the member 54 will be held stationary and the lworm also held dur-l ingl the inward travel of the ram into the fuif-y nace. Y

It will now be seen that I have provided a reversing and reciprocating mechanism of general utility which may be manually controlled to permit it to reciprocate continuously in accordance with a predetermined movement, orthe parts may be stopped at will.

The device is safe, owing to the presence of the shearing pin 85 and will not be broken ifan obstruction is met by the ramror other body being moved. l A mechanical movement of this kind is etlicient and maybe easily made and assembled asthere are but few parts andthese are of simple design. The reciprocatingfmechanism may be. completely housed in a casing and suitablyfoiled and protected i from dustjj This mechanical movement permits a direct thrust upon the ram and no force o is lost in lateral pressure upon the ram casing. v

Various other advantages will be apparent to one rskilledinthe artgand it is to be understood thatL this invention is notlimited to the particular mechanism and construction illustrated inthe drawings and herein described limited by' the claims appended except as'. hereto. y

. InV view of the above disclosure, itwillbe within the capabilities of one skilled in this i artfto rearrange the parts so that the nut will be connected to reciprocate the ram, and the claims are to vbe given this interpretation ascovering such equivalent arrangements.V

Having thus described my inventioinvvhat ,parti I'claim asnew Patentisf: ,fi

'Y l. 'A reciprocatingmechanism comprising` a nut'af-n'd` a screw threaded therein, means to hold one j part -immovable longitudinally,

anddesire to secu-reby Letters y means permitting thefother part to move aX- v ially, means torotat'e the longitudinally :immovable part in one direction, meansl to rotate the axially'movable part inthe same direction at-a higher rate^ofspeed,*a clutch effective` to hold `the axially movable partrotatably Y stationaryv or permitrotation thereof, and means operatedby thel axially movable part effective' to throwjthe clutchand thus cause said part to reciprocate.;`

2'.y A reciprocating mechanism comprising a nut and ia, screw threaded therein, means to hold one' part 'immovable' longitudinally, means' permitting theother `part to move aX- y iallj,f-,fin'eans to rotate the longitudinally immovable part in yone,direction,means to rotate the axially movable-part inthe same direc-` tion at ahigh'erfra'te vofspeed, Va clutch effectiveto "hold the' axially-movable fpart rotat-V ably stationary or permit'rotation thereof, y means operated by the axially movablepartfv` i effective to throvvl the clutch and thus cause f `saidpart to reciprocate, and'inanually controlled -means eiective to' stop the recipro-v Y 3. A reciprocatingmechanism comprising ,o

cationfof said part.'

a nut "and a 'screwfthi'eaded therein',y means to hold kone part'iinino'vable longitudinally while i'iermitting rotation thereof, means perinittin theother palit'to inoveaxiallyfmeans vto rotatethe nut andthe screw in the same A a rotatable longitudinallyl immovable. .Y nut therefor,

means to rotate the vnut", means to rotate the worm i liii `the vsame direction at' a faster rate,

and' means effective to permitk rotation of the Worm orhol'd itrotatably stationary and 5. A reciprocating:mechanism comprising :a rotatable`- longitudinallyV immovable nut, a wo-rm tlireadedtherein andmounted for `ro-` v tative and' longitudinal movement, .means -to s rotate the-nut in one direction,- means to `ro`-, tate the wormy in the-same direction at a high .thereby cause.'reciprocating'motion thereof -relative to the'rotatednut er ratefof speed, aclut'ch efectivejto permit rotation Aof the wormll or `to `hold the Vworm f stationary, kand means operated by movement Yof the worm effective to 'throw the clutchk to Ypermit"continuous reciprocation ofthe worm. 6.V Al reciprocating mechanism comprising a nut, a worm threaded therein, one part be-lr y ing' Vlongitudinally and rotatably'movable relative to the other, vmeans torotate both 55 t f n' Worm rotatablystationary and `cause'longi- 1 tudinalr movementof the raamV o r perm-1t rotai parts at diiferent; speeds, a clutch mechanism effective to prevent or permit rotation of the longitudinally movable part, and manually-controlled means Vto permit both parts to rotate at the samey speedand prevent relative longitudinal movement thereof.

7. A reciprocating mechanism comprising f a rotatable nut, a longitudinally movable and rotatable rWorm threaded Within the nut, means to rotate the nut in one direction and the worm in the same direction at a higher rate of speed, a clutch mechanism effective to prevent rotation of the Worm or permit rotation thereof,` means operated by movement .of the Worm effective to throw the clutch and permit reciprocation of the Worm,A and manually controlled means toY render the clutch in-l operative and permit the Worm to rotate with the mit and be longitudinallyimmovable.

8. A reciprocating mechanism comprising ya nut and a worm threaded therein for relative rotative and longitudinal movement, meansjto hold one of said members longitudinally immovable7 means to rotate the nut, means to rotate the Worm to causelongitudi- 'fnal movement ofone membeigmeans to prevent rotation of thel longitudinally movable Vmember at stated intervals While the other rotates and cause movement of the Worm through the nut, and means effective7 if the cud thrust 'of the longitudinally movable member is excessive, to` permit rotation thereof with the other and prevent further endwise movement.

9, A reciprocating mechanism comprising a rotatable nut, a Worm threaded therein for rotative iaud longitudinalV movement, means to rotate the nut, means torotate the Worm at a differentrate, means to prevent rotation of the Worm at stated. intervals and cause longitudinal movement thereof through the rotatmgnut, and'means effectivey if thejend thrust of theaworm is 'toogreat to permit prevent furrotation thereof with the mit and ther endwise movement.- A

- l0. A reciprocating mechanisn'i comprising a reciprocable ram, a longitudinally movable rotatable ivorm connectedtosad ram and arranged to pushdirectlvv thereagainst in the direction of movement Vof the ram, a rotatable iongitudinally immovable nut mounted on saldi .vorm, means to rotate the nut ini one direction, means to rotate the Worm in the lsame direction at a rate higher than that of the nut;` andfmeans effective to `hold' the tien of the. Worm'and canse the ram to move ,in the opposite direction.- Y Y Y l Signed at lVorlcester, Massachusetts, this 12th day of Se];vtember,l924.

DALLAS vi1enArminia. 

